1Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.2Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.3Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.4Clinical Institute of Pathology, Medical University of Vienna, Vienna, Austria.5Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.6Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.7Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.8Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.9Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.10Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria. pascal.baltzer@meduniwien.ac.at.

METHODS: This retrospective IRB-approved study evaluated consecutive suspicious (BI-RADS 4) breast lesions only visible on MRI that were referred to our institution for MRI-guided biopsy. All lesions were evaluated according to the Tree flowchart for breast MRI by experienced readers. The Tree flowchart is a decision rule that assigns levels of suspicion to specific combinations of diagnostic criteria. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic accuracy. To assess reproducibility by kappa statistics, a second reader rated a subset of 82 patients.